This is generally known as the ApoE4 allele of ApoE and is associated with increased risk of Alzheimer's. 20-25% of individuals are heterozygous for this variant, and 1-2% are homozygous. Data from Khachaturian et al. suggests an average 7% of all individuals developed Alzheimer's by the age of 80; when this is split by ApoE4 status: 10% of ApoE4 heterozygotes (3% increased attributable risk), 40% of ApoE4 homozygotes (33% increased attributable risk), and 5% of non-carriers (2% decreased attributable risk). Notably, their model suggests 70-75% of people would eventually develop Alzheimer's by the age of 100 regardless of ApoE4 genotype (and 25-30% are resistant, regardless of genotype), but that ApoE4 variants shift the disease onset to occur significantly earlier (4 years earlier for heterozygous carriers, 13 years for homozygotes).

This is also called the "Pi Z" or "Z" allele. When homozygous (acting in a recessive manner) this variant is the major cause of severe alpha-1-antitrypsin deficiency (95% of cases) which often leads to emphysema or chronic obstructive pulmonary disease (COPD) and liver disease in adults and children. Heterozygosity for this variant may also be associated with increased rate of lung or liver problems, especially when combined with another variant with reduced function (compound heterozygous).

This common variant has been associated with arterial stiffness and, in Japanese, a small increased risk of myocardial infarction (MI, a.k.a. heart attack). This last observation supported a dominant effect for this variant and, assuming a lifetime risk of 15% for MI, we estimate carriers have an additional risk of 0.5-3%.

This common variant (HapMap allele frequency of 31.3%) in a protein involved in folate (B9) and cobalamin (B12) metabolism and is often reported as "MTRR I22M" (an alternative transcript position). Mothers homozygous for this variant are associated with having around a increased chance of a child with Down syndrome (risk of 0.4%, average risk in population is 0.25%). Notably, age plays a far larger role in the rate of Down syndrome (risk is 4.5% for a mother 45-years-of-age), and it is unknown how this variant may combine with the effect of age. There are conflicting reports associating this variant with incidence of neural tube defects, possibly when combined with MTHFR A222V.

This common noncoding genetic variant has an allele frequency of ~30% and is associated with an increased risk of hypertension. If ~25% of non-carriers have hypertension, Bonnardeaux et al's data predict ~4% increased risk of hypertension per copy of this variant. This SNP is in the 3' noncoding region of the AGTR1 transcript (angiotensin II type 1 receptor), also known as AT2R1 or AT1R, which is a target of hypertension drugs.

This variant in a growth factor gene is associated with variation in TGFB1 levels; this has been associated with various pathogenic and some protective effects, including: more hepatic fibrosis progression in hep C patients, lower risk of cleft palate, anticorrelation with longevity, higher risk of myocardial infarction and lower risk of hypertension.

In a study of a UK population this variant was associated with a small increased risk of osteoporosis and osteoporotic bone fractures, with each copy of the variant presumed to have an additive effect. A study in Chinese young men failed to find an association with peak bone density.

Associated with increased risk of prostate cancer in individuals who already have a family history of prostate cancer, but studies have been unable to replicate this finding in sporadic (non-familial) prostate cancer cases.

This variant is associated with a slightly increased risk of tuberculosis. It is unclear whether it is itself causal, or in linkage disequilibrium with some other causal variant that has a stronger effect.

This nonsynonymous SNP is associated with Wolfram Syndrome (known as DIDMOAD), which is characterized by early-onset non-autoimmune diabetes mellitus, diabetes insipidus, optic atrophy, and deafness) and to adult Type Two Diabetes Mellitus. The WFS1 gene maps to chromosome 4p16.3. The variant has been shown to be statistically associated with type II diabetes in six UK studies and one study of Ashkenazi Jews (Sandhu, M., et al., Minton et al.).

This is a common variant was first reported as a polymorphism. It has since had mixed associations with cancer: Storey et al. conclude a 7x *increased* risk of HPV cancer for homozygotes vs hets, but Jones et al. find a 1.98x *decreased* risk for colorectal cancer. This variant may have significant impact on particular cancers, but it is unclear what effect it has on the overall burden of cancer.

This rare variant (around 1% allele frequency) is hypothesized to cause carboxypeptidase N deficiency in a recessive manner, especially if combined with a more severe variant. However the findings lack statistical sigificance: only a single case study of an affected individual links this variant to causing the disease. There aren’t any follow-up in vitro studies testing whether this variant affects protein function.

This recessive protective variant confers resistance to norovirus (which causes stomach flu). 20% of Caucasians and Africans are homozygous for this variant and are "non-secretors": they do not express ABO blood type antigens in their saliva or mucosal surfaces. Most strains of norovirus bind to these antigens in the gut, and so this non-secretor status confers almost total resistantance to most types of norovirus. There are notable exceptions, some strains of norovirus bind a different target and are equally infectious for secretors and non-secretors.

This variant is associated with some protective effects for prion disease -- individuals homozygous for this variant are less susceptible to Creutzfeldt-Jakob, and Papua New Guinea individuals heterozygotes at this site are less susceptible to kuru.

Associated with a decreased risk for age related macular degeneration (ARMD). Homozygotes for this have a 4-5% decreased attributable risk (3-4% vs. average 8% risk), heterozygotes have slightly lower than average risk (7%). Non-carriers have an increased risk (12-13%). ARMD impairs sharp vision as age progresses. While there is no cure, treatment can slow progression of the disease and environmental factors (smoking and obesity) contribute to higher risk.

This variant is associated with decreased risk of type 2 diabetes. It is unclear whether this variant has additive effects, or acts in a dominant or recessive manner. Assuming diabetes has a lifetime risk of 36%, we estimate a decreased risk of around 1-2% per copy of this variant.

The reference genome variant for this allele has been associated with a slight increased risk of multiple sclerosis. Thus, this variant can be treated as a "protective" variant -- carriers of this variant are slightly less likely to have MS. Because the disease is rare and the effect of this variant is not very strong, the absolute decreased risk for carriers of this variant is less than .05% (less than 1 in 2000).

Associated with exfoliative glaucoma & syndrome (XFG & XFS) in various populations, but with contradicting results (protective in Caucasians, pathogenic in Japanese). Based on this it seems the variation itself -- although it affects protein structure -- is not itself causing disease. Instead it is likely associated with other nearby causal variants. As such, it is evaluated as benign by GET-Evidence (which focuses on reporting causal variants). See detailed variant report for disease risk associations.

Presumed benign. Although this variant was implicated in causing ectodermal dysplasia in a recessive manner in two Pakistani families (one of which was large and consanguineous), GET-Evidence reports that the variant has been seen in 5 out of 114 random control chromosomes. This strongly contradicts a severe pathogenic effect.

This variant is associated with "taster" status of PTC, along with 49P and 262A. Due to linkage disequilibrium, the independent effects of positions 296 and 262 is unclear. The presence of 49P confers taster status in a dominant fashion, but in the absence of 49P, the presence of 262A/296V is still positively associated with tasting PTC.

Probably benign. One report linked this variant to high triglycerides, but a later paper found a nearby SNP with similar association and suggests that both findings are caused by linkage to an undiscovered causal variant.